The detention of Agriculture Minister Salah el-Din Helal and his aides comes after Egyptian prosecutors issued a gag order last week over the investigation.

A statement by Ali Omran said that Helal and three other ministry officials also were detained pending an investigation. The statement alleged that the four officials accepted gifts in exchange for the reallocation of a parcel of state land, including a sports club membership, high-end clothing, mobile phones, expensive meals, payment for 16 people to go on a religious pilgrimage and a luxury housing unit.

In an interview Sunday with the private CBC television network, Helal said, "There are no corruption cover-ups in the Ministry of Agriculture," without elaborating on the case. Helal could not be immediately reached for comment Monday and it wasn't clear if he had a lawyer.

The Egyptian government long has been plagued by corruption allegations, particularly regarding land deals. El-Sissi routinely emphasizes that he is fighting corruption.

Many officials from the era of ousted autocrat Hosni Mubarak have won a series of acquittals in recent months in corruption-related cases. El-Sissi has pledged to go after corrupt officials and Helal's detention marks the biggest case yet to be brought forward by his administration.